DE1204667B - Process for the preparation of asymmetrical Thionothiolphorsphorsaeureestern - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

Number:
File number:
Registration date:
Display day:

C07f

German class: 12 ο - 23/03

1204 667
F41675IVb / 12o
4th January 1964
November 11, 1965

The invention relates to a process for the preparation of asymmetrical thionothiol phosphoric acid esters the general formula

Method of making unbalanced Thionothiol phosphoric acid esters

RO
RO '

P -

(CH ₂ ) _re - R "

in which R represents a straight-chain alkyl and R 'represents a branched alkyl or a cycloalkyl radical, while R "represents an alkyl mercapto, aryl mercapto or haloaryl mercapto radical and the index η has the value 1 or 2.

The symbol R preferably denotes straight-chain low molecular weight alkyl groups with 1 to 4 carbon atoms, like the methyl or ethyl radical; R 'stands for branched alkyl radicals, preferably with 3 to 6 carbon atoms, ζ. B. for the isopropyl, sec. And tert-butyl and pinacolyl as well as the cyclohexyl radical.

The radical R ″ primarily represents low molecular weight alkyl mercapto groups. Examples include: the methyl, ethyl, propyl and butyl mercapto radicals; furthermore, R "can also be a phenyl mercapto and halogen (preferably chlorine) phenyl mercapto radicals.

It has been found that compounds of the above general formula smoothly and with good Yields are obtained if unsymmetrical 0,0-dialkyl- or O-alkyl-O-cycloalkylthionothiolphosphoric acids are used the general formula

^R0 \ I

RO

P-SH

either in the form of their salts or in the presence of acid binders in alkyl halide groups Compounds of the general formula

implements.

In the aforementioned formulas, the symbols R, R ', R "and η have the meaning given above, while Hai stands for a halogen atom.

The reaction according to the process is preferably carried out in the presence of inert organic solvents carried out. Low molecular weight aliphatic in particular have proven useful for the stated purpose Ketones and nitriles such as acetone, methyl ethyl, methyl isopropyl and methyl isobutyl ketone as well Applicant:

Paint factories Bayer Aktiengesellschaft,

Leverkusen

Named as inventor:

Dr. Reimer Colin, Wuppertal-Elberfeld;

Dr. Dr. H. c. Gerhard Schrader,

Wuppertal-Cronenberg;

Dipl.-Agr. Dr. Günter Unterstenhöfer,

Opladen

Aceto- and propionitrile, but also hydrocarbons, for example benzene, toluene or xylene.

Furthermore, it has proved advantageous to carry out the inventive method at low to moderately elevated temperatures (30 to 100 ⁰ C, preferably 40 to 8O ⁰ C), and also the reaction mixture after combining the starting components for some time (1 to 3 hours), optionally with heating, to the above-mentioned temperatures. In this case, the process products are obtained in excellent purity and in particularly good yields.

The asymmetrical ones to be used as starting materials for the implementation according to the process 0,0-dialkyl- or. O-alkyl-O-cycloalkylthionothiol phosphoric acids can be done according to methods known per se (cf. for example G. Schrader, "The development of new insecticidal phosphoric acid esters", 3rd edition, Verlag Chemie, 1963, p. 112, or US Pat. No. 2,983,644) as follows getting produced:

A mixture of 2 moles each of a straight-chain and a branched aliphatic is stirred or a cycloaliphatic alcohol at room or slightly elevated temperature with 1 mol Phosphorus pentasulfide. The mixture of the desired ones which forms in the course of 5 to 10 hours Thionothiolphosphoric acid and its two corresponding symmetrical homologues is then used by fractional washing out of the water

509 737/406

soluble fractions or leaching out of the more acidic-reacting component by means of a deficit separated by alkali. Those that are easily accessible on a technical scale using this process Salts of the unsymmetrical Ο, Ο-dialkyl or O-alkyl-O-cycloalkylthionothiolphosphoric acids are pure enough for further implementation according to the invention. Preferably find the appropriate ones Alkali and ammonium salts use.

The products of the process are mostly viscous, pale yellow, water-insoluble oils, some of which can be distilled If they cannot be distilled without decomposition even in a high vacuum, the substances can by heating to a slightly elevated temperature (50 to 80 ° C) under greatly reduced Pressure (1 to 2 Torr) freed from the last volatile components and in this way kept pure. However, some of the compounds which can be prepared according to the process are also in crystalline form at. In this case they can be

20 cleaning out the common solvents or solvent mixtures further.

The asymmetrical thionothiol phosphoric acid esters obtainable according to the invention are distinguished excellent biological properties, especially insecticidal and acaricidal properties. You are against Insect pests of the most diverse genera, such as spider mites, aphids, grain beetles and caterpillars equally effective. In addition, the process products have a low solubility in water, which causes a reduction in phytotoxicity. Finally, they show a significant thermal Stability. A maximum of biological effect is achieved with the 0-methyl-O-branched-alkyl compounds and among these again achieved with the 0-methyl-O-isopropyl derivatives.

Due to their excellent pesticidal properties, the process products are used as pesticides or use of pesticides.

Comparative experiments

Connect
manure

Active ingredient (constitution) Insecticidal and acaricidal effectiveness

Application against

Active ingredient concentration
in O

Killing of pests in%

CH ₃ O _x II

; P-S-CHa-SC ₂ H ₅
iC ₃ H ₇ O ^x

(according to the method, example 1) aphids

CH ₃ O
CH ₃ O

PS-CH ₂ -SC ₂ H ₅ aphids

0.01

0.001

0.0008

0.01
0.001

100

100

40

50 0

(known from German patent specification 917 668, example 11)

PS-CH ₂ -SC ₂ H ₅
1-C ₃ H ₇ O ^x

(according to the procedure, example 4)

S.
C ₂ H ₅ O \ II

) P-S _{-CH 2 -SC 2} H ₅
C ₂ H ₅ O /

(known from German patent specification 917 668, example 6)

CH ₃ O _x I.

1-C ₃ H ₇ O- (according to the method, example 7)

P - S - CH ₂ - CH ₂ - SC ₂ H ₅ ¹ spider mites
(normal
sensitive)

Spider mites
(normal
sensitive)

Spider mites

0.001

100

0.001

0.0001

100

CH ₃ O

P - S - CH ₂ - CH ₂ - SC ₂ H ₅ spider mites

0.0001

50

CH ₃ O

(known from German patent specification 917 668, example 12)

continuation

Connect
manure

Insecticidal and acaricidal effectiveness

Application against

Active ingredient concentration
in ° / o

Killing of pests in%

P-CH ₂ - CH ₂ - SC ₂ H ₅

sec.-QHgO ^/
(according to the procedure, example 11)

C ₂ H ₅ O _x I.

C ₂ H ₅ O-

P - S - CH ₂ - CH ₂ - SC ₂ H ₅

(known from German patent specification 917 668. Example 3)

1-C3H7

(according to the procedure, example 14) p

H λ - \

; p-s-CH ₂ -s- <f> -α

CH ₃ O _x

CH ₃ O

(known from "Chemical Week" of September 5, 1959, p. 37)

C ₂ H ₅ O
iC ₃ H ₇ O

PS-CH ₂ -!

Cl

(according to the procedure, example 16) p

C ₂ H ₅ O
C ₂ H ₅ O

PS-CH ₂ -

(known from US Pat. No. 2,793,224)

Cockroach cockroach

Caterpillars

Caterpillars

To fly

To fly

0.1

0.1

0.5

0.02

0.02
0.1

0.004

0.004

100

100

0 80

40

The following examples provide an overview of the claimed method.

CH ₃ O _x I.

example 1
S.

1-C ₃ H ₇ O

PS-CH ₂ -SC ₂ H ₅

g (0.5 mol) of 0-methyl-O-isopropyl-thionothiolphosphoric acid sodium are dissolved in 400 cm ^{3 of} acetonitrile. To this solution are added at 40 to 5O ⁰ C 55 g Chlormethylthioäthyläther, the reaction mixture is then stirred for a further 1 hour, then cooled to room temperature and the batch is poured into 400 cm ³ of ice water. The precipitated Ul is taken up in 300 cm ^{3 of} benzene, the benzene solution is washed with water until it reacts neutral and dried over sodium sulfate. In the subsequent fractional distillation, after evaporation of the solvent, 87 g (corresponding to 67% of theory) of the O-methyl-O-isopropyl-S- (ethylmercaptomethyl) -thionothiolphosphoric acid ester with a boiling point of 0.01 = 79 ° C. are obtained. The mean toxicity (DLso) of the compound in rats is 5 mg per os per kilogram of animal. 70% of the spider heads are killed by 0.0001% solutions.

Example 2

S.
CH ₃ O _x H

65 sec - C ₄ H ₉ O -

PS-CH ₂ -SC ₂ H ₅

111 g (0.5 mol) of O-methyl-O-sec-butylthionothiolphosphoric acid sodium are dissolved in 400 cm ^{3 of} acetone

tonitril, added to this solution with stirring at 30 to 40 ⁰ C. 55 g Chlormethylthioäthyläther, the reaction mixture is then stirred for 1 hour at 40 ° C and then operates, as described in the preceding example, on. There are 112 g (corresponding to 82% of theory) of O-methyl-O-sec-butyl-S- (ethylmercaptomethyl). - Thionothiolphosphoric acid ester with a boiling point of 0.01 = 94 ° C. In the rat per os, the compound has an average toxicity (DLso) of 10 mg per kilogram of animal.

Wheat beetles are still 100% killed by 0.0001% solutions of the ester.

PS-CH ₂ -SC ₂ H ₅

To a solution of 124 g (0,5MoI) O-methyl-O-cyclohexyl-thionothiolphosphorsaurem sodium in 400 cm ³ of acetonitrile is added with stirring at 30 to 40 ⁰ C. 55 g Chlormethylthioäthyläther, the mixture was then stirred for 2 hours at 40 ° C and then cool it down to room temperature. The reaction mixture is then ^{poured into 400 cm 3 of} ice water, the precipitated oil is taken up in 300 cm ^{3 of} benzene, the benzene solution is washed with water until it reacts neutral and dried over sodium sulfate. After distilling off the solvent, the residue is heated under a pressure of 1 Torr for a short time to a bath temperature of 70 ⁰ C. The O-methyl-O-cyclohexyl - S - (äthylmercapto - methyl) - thionothiolphosphorsäureester in this way in the form of of a pale yellow, water-insoluble O'les obtained. The yield is 118 g (corresponding to 79% of theory).

Analysis for a molecular weight of 300:

Calculated ... S 32.0%, P 10.3%;
found ... S 31.0%, P 10.7%.

The mean toxicity (DL50) of the compound in rats is 25 mg per os per kilogram of animal.

40% of spider mites are killed by 0.001% solutions of the ester.

Example 4

C ₂ H ₅ O
1-CsH ₇ O '

P- _{S-CH 2} -SC 2 H 5

112 g (0.5 mol) of O-ethyl-O-isopropyl-thionothiolphosphoric acid sodium are dissolved in 400 cm ^{3 of} acetonitrile. 56 g of chloromethylthioethyl ether are added to the resulting solution with stirring at 40 ^° C., the mixture is then stirred for a further 1 hour at 40 ^° C. and then worked up as described in the preceding examples. 108 g (corresponding to 79% of theory) of the O-ethyl-O-isopropyl-S- (ethylmercapto-methyl) -thionothiolphosphoric acid ester with a boiling point of 0.01 = 87 ° C. are obtained.

The mean toxicity (DL50) of the compound in rats is 5 mg per os per kilogram of animal.

Spider mites are 100% killed by 0.001% solutions.

C ₂ H ₅ O _x H

Example 5
S.

sec-C ₄ H ₉ O

PS-CH ₂ -SC ₂ H ₅

A solution of 120 g (0.5 mol) of O-ethyl-0-sec-butyl-thionothiolphosphorsaurem sodium in 400 cm ³ of acetonitrile is added under stirring at 40 ⁰ C with 55 g Chlormethylthioäthyläther. After the addition is complete, the mixture is stirred for 1 hour at the stated temperature, then worked up, as already described several times, and 108 g (corresponding to 75% of theory) of the O-ethyl-O-sec are obtained. -butyl-S - (ethylmercapto-methyl) -thionothiolphosphoric acid ester with a boiling point of 0.01 = 94 ° C.

In the rat per os, the ester is a medium toxicity (DL ₅ o) of 5 mg per kilogram of animal.

Spider mites become 100% from 0.001% solutions of the compound and aphids still 80% killed.

Example 6

C ₂ H ₅ O

PS-CH ₂ -SC ₂ H ₅

135 g (0.5 mol) of sodium O-ethyl-O-cyclohexyl-thionothiolphosphate are dissolved in 400 cm ^{3 of} acetonitrile. 55 g of chloromethylthioethyl ether are added to this solution at 40 ^° C. with stirring, the mixture is then stirred for a further hour at the specified temperature, the reaction mixture is then cooled to room temperature and poured into 400 cm ^{3 of} ice water. The precipitated oil is taken up in 300 cm ^{3 of} benzene, the benzene solution is washed with water, dried over sodium sulfate and finally the solvent is distilled off in vacuo. The residue is heated for a short time under a pressure of 1 Torr at a bath temperature of 65 ⁰ C and obtained as the O-ethyl-O-cyclohexyl-S-iäthylmercapto-methyty-thionothiolphosphorsäureester as a yellow, water-insoluble oil. The yield is 128 g (corresponding to 82% of theory).

Analysis for a molecular weight of 314:

Calculated '... P 9.9%, S 30.6%;
found ... P 10.4%, S 30.3%.

In the rat per os the average toxicity (DL ₅ o) is the compound 5 mg per kilogram of animal.

Caterpillars are still 100% killed by 0.01% solutions of the ester.

CH ₃ O
1-C ₃ H ₇ O

Example 7

- S - CH ₂ - CH ₂ - SC ₂ H ₅

105 g (0.5 mol) of sodium O-methyl-O-isopropylthionothiolphosphoric acid are dissolved in 400 cm ^{3 of} acetonitrile, 63 g of 2-chloroethylthioethyl ether are added to the resulting solution with stirring at 70 to 80 ° C., and the mixture is then stirred for a further 1 hour 80 ⁰ C and then cools it down to room temperature. The reaction mixture is then poured into 400 cm ^{3 of} ice

ίο

water poured; the precipitated oil was taken up in 30Öcm ³ benzene, the benzene solution was washed with water and dried over sodium sulfate. In the subsequent fractional distillation of the organic phase, after evaporation of the solvent, 89 g (corresponding to 65% of theory) of the O - methyl - O - isopropyl - S - (2 - ethylmercaptoethyl) thionothiolphosphoric acid ester of Kp.o, oi QQOr-i

The mean toxicity (DL50) of the compound is 10 mg per kilogram of rat orally.

Aphids become from 0.001% 100% and spider mites from 0.0001% solutions of the ester still 100% killed.

Example 8

S.
CH ₃ Ö \ "

Spider mites are 100% killed by 0.01% solutions of the ester.

Example 10

; P - S - CH ₂ - CH ₂ - SC ₂ H ₅

1-C ₃ H ₇ O '

sec-C ₄ Hg0

P - S - CH ₂ - CH ₂ - SC ₂ H ₅

20th

111 g (0.5 mol) of sodium O-methyl-0-sec-butyl-thionothiolphosphate are dissolved in 400 cm ^{3 of} acetonitrile. With stirring, 63 g of 2-chloroethylthioethyl ether are added to this solution at 70.degree. C., the mixture is then stirred for a further 1 hour at 80.degree. C. and then worked up as described in Example 7. There are 113 g (corresponding to 78% of theory) of the C ₂ H ₅ O

O-methyl-O-sec-butyl-S- (2-äthyImercapto-ethyl) -thionothiolphosphoric acid ester of bp 0.01 = 92 ° C 30 sec-CdH & O obtain.

The mean toxicity (DL50) of the compound is on rats per os 20 mg per kilogram of animal.

Spider mites are still 90% killed by 0.001% solutions of the ester, and caterpillars with it 0.0% solutions are destroyed by 10%.

112 g (0.5 mol) of sodium O-ethyl-0-isopropyl-thionothiolphosphate are dissolved in 400 cm ^{3 of} acetonitrile. 63 g of 2-chloroethylthioethyl ether are added to this solution at 75 ° C. with stirring, the reaction mixture is then heated to 75 ° C. for a further hour and then worked up as described in the preceding examples. 121 g (corresponding to 84% of theory) of the O-ethyl-O-isopropyl-S- (2-ethylmercapto-ethyl) -thionothiol phosphoric acid ester with a boiling point of 0.01 = 92 ° C. are thus obtained.

The mean toxicity (DL50) of the ester in rats per os is 10 mg per kilogram of animal.

Aphids are killed by 0.001% solutions of the compound to 50%, spider mites to 80%.

Example 11

P - S - CH ₂ - CH ₂ - SC ₂ H ₅

CH ₃ O-

Eg 1 9

P - S - CH ₂ - CH ₂ - SC ₂ H ₅

40

63 g of 2-chloroethylthioethyl ether are added to a solution of 124 g (0.5 mol) of sodium O-methyl-O-cyclohexyl-thionothiolphosphoric acid in 400 cm ^{3 of} acetonitrile, while stirring, and the mixture is then heated to 80 for a further hour ⁰ C, then cools it down to room temperature and dilutes the reaction mixture with 400 cm ^{3 of} ice water. The oil which has separated out is then taken up in 300 cm ^{3 of} benzene, the benzene solution is washed with water and dried over sodium sulfate and the solvent is distilled off in vacuo. The residue is heated for a short time under a pressure of 1 torr to a bath temperature of 70 ° C. and thus the O-methyl-Ö-cyelohexyl-S- (2-ethyI-mereapto-ethyl) -thionothioiphosphoric acid ester is obtained in the form of a yellow, water-insoluble ester Oil. The _yield (10 prey is 120 g (corresponding to 76% of theory).

Analysis for a molecular weight of 314:

Calculated ... S 39 * 6%, P 9.9%;

found ... S 30.2%, P 10.6%. _fti .

In the rat per os, the compound shows a mean toxicity (DLso) of about 60 mg per kilogram Animal.

63 g of 2-chloroethylthioethyl ether are added to a solution of 120 g (0.5 mol) of sodium O-ethyl-O-sec-butyl-thionothiolphosphoric acid in 400 cm ^{3 of} acetonitrile, while stirring at 75 ° C., and the mixture is then heated for 1 hour 75 ⁰ C and then works it up, as already described several times. 119 g (corresponding to 79% of theory) of the O-ethyl-O-sec. - butyl - obtained from -thionothiolphosphorsäureesters Kp.0,01 = 103 ⁰ C S - (ethyl 2 - - äthylmercapto).

The mean toxicity (DLso) of the compound is 20 mg per kilogram of rat per os.

Spider mites are 100% killed by 0, oil% solutions of the ester.

Example 12

C ₂ H ₅ O _x II

S-CH ₂ - CH ₂ - SC ₂ H ₅

135 g (0.5 mol) of sodium O-ethyl-O-cyclohexylthionothiolphosphate are dissolved in 400 cm ^{3 of} acetonitrile, 63 g of 2-chloroethylthioethyl ether are added to the resulting solution at 80 ° C., and the mixture is stirred for a further hour at 80 ° C. and cooled it is then reduced to room temperature and the reaction mixture is diluted with 400 cm ^{3 of} ice water. The oil which has separated out is taken up in 300 cm ^{3 of} benzene, and the benzoic solution is washed with water and dried over sodium sulfate. After the solvent has been distilled off, the residue is heated under a pressure of 1 Torr for a short time at a bath temperature of 70 ° C. In this way, the O - ethyl - O - cyclohexyl - S - (2 - ethylmercapto - ethyl) thionothiolphosphoric acid ester is used as the yellow, water

5OS 737/406

Example 14

20th

CH ₃ O \ II
(CH ₃ ) ₃ C \ / PS-CH ₂ -CH ₂ -SC ₂ H ₅

; ch— o ^/

CH ₃ /

38 g of 2-chloroethylthioethyl ether are added at 60 ° C. to a solution of 75 g (0.3 mol) of sodium O-methyl-O-pinacolyl-thionothiolphosphoric acid in 200 cm ^{3 of} acetonitrile, and the mixture is then heated to 70 to 80 for a further hour ° C, it then cools to room temperature and the reaction mixture is poured into 200 cm ^{3 of} ice water. The precipitated oil is taken up in 200 cm ^{3 of} benzene, the benzene solution is washed with water, dried over sodium sulfate and the solvent is distilled off in vacuo. The remaining residue is heated for a short time under a pressure of 1 Torr to a bath temperature of 70 ° C and thus 83 g (corresponding to 87% of theory) of O-methyl-O-pinacolyl -S - (2-ethylmercapto-ethyl) -thionothiolphosphoric acid ester in the form of a yellow, water-insoluble oil.

Analysis for a molecular weight of 316:
Calculated ... P 9.8%, S 30.4%;
found ... P 10.0%, S 30.2%.

get insoluble oil. The yield is 128 g (corresponding to 78% of theory).

Analysis for a molecular weight of 328:
Calculated ... P 9.5%, S 29.3%; ,

found ... P 10.1%, S 28.9%.

The compound has an average toxicity (DL50) of 50 mg per kilogram in the rat per os Animal.

Aphids are 100% destroyed by 0.01% solutions of the ester.

Example 13

15 Analysis for a molecular weight of 343:
Calculated ... Cl 10.3%, S 28.0%; P 9.1%;
found ... Cl 10.0%, S 28.1%, P 10.2%.

The mean toxicity (DL50) of the compound in rats is 25 mg per os per kilogram of animal.

Spider mites are still 95% killed by 0.001% solutions of the ester.

Example 15

CH ₃ O
sec-C ₄ H ₉ O

A solution of 112 g (0.5 mol) of sodium O-methyl-O-sec-butyl-thionothiolphosphoric acid in 400 cm ^{3 of} acetonitrile is admixed with 97 g of chloromethyl (4-chlorophenyl) thioether while stirring at 50 to 60 ° C . The mixture is then heated to 80 ° C. for 1 hour, then cooled to room temperature and worked up as described in the previous example. The O-methyl-O-sec-butyl-S- (4-chlorophenylmercapto-methyl) -thionothiolphosphoric acid ester is obtained in the form of a yellow, water-insoluble oil. The yield is 127 g (corresponding to 71% of theory).

Analysis for a molecular weight of 357:
Calculated ... P 8.7%, S 26.9%, Cl 9.9%;
found ... P 8.8%, S 26.4%, Cl 9.8%.

The mean toxicity (DL ₅ o) the compound is 25 mg per kg of rat when administered orally.

80% of spider mites are destroyed by 0.001% solutions of the ester.

40

45

Example 16

C ₂ H ₅ O
1-C ₃ H ₇ O -

PS-CH ₂ -

105 g (0.5 mol) of sodium O-methyl-O-isopropyl-thionothiolphosphate are dissolved in 400 cm ^{3 of} acetonitrile. 96 g of chloromethyl (4-chlorophenyl) thioether - dissolved in 50 cm ^{3 of} acetonitrile - are added to this solution with stirring at 50 to 70 ° C., the mixture is then heated to 70 ° C. for a further hour and then cooled to room temperature and pour the reaction mixture into 400 cm ^{3 of} ice water. The precipitated oil is taken up in 300 cm ^{3 of} benzene, the benzene solution is washed with water and then dried over sodium sulfate. After distilling off the solvent in vacuo, the remaining residue is heated after a short time under a pressure of 2 Torr at a bath temperature of 6O ⁰ C. In this way, 129 g (corresponding to 75% of theory) of O-methyl-O-isopropyl-S- (4-chlorophenylmercaptomethyl) -thionothiolphosphoric acid ester are obtained as a yellow, water-insoluble oil.

112 g (0.5 mol) of sodium O-ethyl-0-isopropylthionothiolphosphate are dissolved in 400 cm ^{3 of} acetonitrile, 97 g of chloromethyl (4-chlorophenyl) thioether are added to this solution at 50 to 60 ° C., and the reaction mixture is then heated 1 hour at the specified temperature and then works it up, as already described several times. 170 g (corresponding to 95% of theory) of the O-ethyl-O-isopropyl-S- (4-chlorophenylmercaptomethyl) -thionothiolphosphoric acid ester are obtained as a pale yellow, water-insoluble oil.

Analysis for a molecular weight of 357:
Calculated ... Cl 10.0%, S 26.9%, P 8.8%;
found ... Cl 10.1%, S 26.4%, P 9.1%.

In the rat per os the ester is a medium toxicity (DL ₅ o) of 20 mg per kilogram of animal.

Spider mites are 100% killed by 0.001% solutions of the compound.

C ₂ H ₅ O «
sec-C ₄ H ₉ O ■

Example 17

; P —S-CH ₂ -

C.

-Cl

To a solution of 135 g (0.5 mol) of O-ethyl-Q-cyclohexyl-thionothiolphosphorsaurem sodium in 400 cm ³ of acetonitrile are added at 60 to 7O ⁰ C. 97 g of chloromethyl (4-chlorophenyl) thioether, the mixture is stirred then another 1 hour at 60 ⁰ C,

120 g (0.5 mol) of sodium O-ethyl-0-sec-butyl-thionothiolphosphate are dissolved in 400 cm ^{3 of} acetonitrile. The same solution is added at 70 ⁰ C ι ο under stirring with 97 g of chloromethyl (4-chlorophenyl) thioether, the mixture is then heated for 1 hour at 60 to 70 ⁰ C and then it operates in the manner described in the preceding examples on. The O-ethyl-O-sec-butyl-S- (4-cl ^ loφhenylmercapto-methyl) -thionothiolphosphoric acid ester is obtained in the form of a pale yellow, water-insoluble oil. The yield is 145 g (corresponding to 78% of theory).

Analysis for a molecular weight of 371:

Calculated ... P 8.4%, S 25.9%, Cl 9.6% ;.
found ... "P 8.9%, S 25.9%, Cl 9.5%.

The mean toxicity (DL50) of the compound in rats is 25 mg per os per kilogram of animal.

60% of spider mites are killed by 0.001% solutions of the ester.

Example 18

it then works up in the manner already described several times and receives 148 g (corresponding to 75% of the Theory) of the O-ethyl-O-cyclohexyl-S- (4-chlorophenylmercapto) -thionothiolphosphoric acid ester as a yellow, water-insoluble oil.

Analysis for a molecular weight of 397:

Calculated ... Cl 9.0%, S 24.2%, P 7.8%;
found ... Cl 9.0%, S 23.9%, P 8.3%.

The mean toxicity of the compound (DL50) is 50 mg per kilogram of rat per os.

Spider mites are still 40% destroyed by 0.001% solutions of the ester.

Claims (1)

Claim: Process for the preparation of asymmetrical thionothiol phosphoric acid esters, characterized in that asymmetrical 0,0-dialkyl- or O-alkyl-O-cycloalkylthionothiolphosphoric acids the general formula 35 40 RO
R'O- P-SH either in the form of their salts or in the presence of acid binders containing alkyl halide groups Compounds of the formula HaI- (CH ₂ ) ^ - R " reacted, where in the aforementioned formulas R stands for a straight-chain alkyl and R 'stands for a branched alkyl or a cycloalkyl radical, while R "represents an alkyl mercapto, aryl mercapto or haloaryl mercapto radical, the index η has the value 1 or 2 and Hal stands for represents a halogen atom. 509 737/406 11.65 © Bundesdruckerei Berlin